Centering device.



F; H. BRENNAN.

CENTERING DEVICE.

APPLICATION FILED JUNE 15. 1911.

Patented Feb. 5, 1918.

2 SHEETS-SHEET 1.

F. H. BRENNAN.

CENTERING DEVICE.

APPLICATION FILED. JUNEI5, 19H.

Patented Feb. 5, 19118.

2 SHEETS-SHEET 2 a'wmzwbo z we 7* mam till lBRhNUIS H. BRENNAN, 0h ALBANY, NEW YORK.

GJEN'JLERING- DEVICE.

hpeotnoatton of Letters Patent.

Patented Fella, a, rare,

a lication filed June it, 1917. serial No. iraooa.

To all whom it may concern."

Be it known that l, FRANCIS H. Bram NAN, a citizen of the United States, residin at Albany, in the county of Albany and tate of New York, have invented certain new and useful llmprovements in Centerin Devices, of which the following is a speci cation.

This invention relates to centering devices and has as its object to provide a centering device which may be readily applied to a piece of work for the purpose of quickly and accurately determining the geometric center thereof and which device may also he employed in scribing a piece of work and in marking the median or center line oi a bar, plate, or other similar piece of work.

Another aim of the invention is to provide a centering device so constructed that it will operate as accurately and as eficiently on the largest as well as the smallest sizes at work to which it is applicable.

in the accompanying drawings:

Figure l is a perspective view at the device illustrating the manner in which the same may he applied to the end of a shalt or other cylindrical hody in orderto determine the geometric center thereof llhg. 2 is a plan view of the device illustrating the manner in which the same is to be employed in determinin' and indicating the median or center line (0% a bar or plate;

Fig, 8 is a similar view illustrating the manner in which the device may he enrployed in determining the geometric center ot a polygonal body or piece ct work;

Figw t is a vertical longitudinal sectional view through the device applied to the end of a shaft;

Fig. 5 is a side elevation plied to the end at a-shatt.

The device embodying the present invention comprises a frame supporting, centrally, a marking or scribing oint and carryin work-engaging mem ers between whic the said oint is centrally located. The frame inclu cs center bars 1 which are arranged in crossed relation, and two pairs at side bars each indicated by the numeral 2. The side bars of each pair at their inner ends are mutually pivotally connected, as indicated by the numeral 3, and at a point midway between their ends the bars of each pair are pivotally connected, as at d, with the corresponding ends of the center bars 1. At their point oi intersection the center bars oi the device ap- 1 support a tubular post 5 which is reduced in dlameter at its lower end, as at 6, and has its said end fitted through openings in the said center bars, a collar 7 bein riveted upon the reduced end of the ost elow the said center bars so as to hol the parts in proper assembled relation and ct permit of relative an ular movement oil the bars 1. Freely slida 1y fitted in the tubular post 5 is a combined centering and scribin pin 8 having a conical pointed end 9 designed to be driven into the work to indicate the center thereof or to mark a line upon work when it is desired to determine and indicate the median or center line thereof. lhe pin 8 is flattened upon one side throu bout a portion of its length, as indicated meral 10, and a set screw 11 is threaded through the wall of the tubular 0st 5 and, by enga ement with the shoul ers at the ends of t e flattened portion 10 of the said pin, is designed to limit the sliding movement of the in in the said post. lilowever, the pin may e held at any desired position of adjustment, as, for exam le, in scribing wort: or drawing the median line thereof, by tightening the said set screw it alter the pin has been brought to the desired position of adj ustrnent,

Depending from the outer end at each of the frame hars is a work-engaging mem her preferably in the nature all a cylindrical post it having its upper end reduced, as at 13, so as to permitot the device being applied to work having a bun, shoulder, or the like, as clearly shown, for example, in Figs. t and 5 of the drawings. While in the present instance the worlcen aging members are in the nature of posts w ich are cylindrical in form, it will be understood that various other forms of said members ma he eInployed. It will he observed by re erence to the drawings that there are, in edect, two pairs of the worlnengaging members or posts 12 and that in all ositlons of adjustment of the frame memhers the said airs of worlcengaging members will be equl-distantly spaced at the opposite sides ot the centering or marking pin 8. It is preferable that the center bars 1 be of greater length than the bars 2 so that the outer ends of the bars Q will he given an increased throw when the frame 1s adjusted for the application of the device to a relatively large piece of work. in other words, when by the nu- Bil the device for application to a large piece of' work, the posts 12 of each pair will be graduall moved away from each other a relative y great distance and this distance will increase with the increased opening or spreading of the frame. Thus when the frame is adjusted for application to a large piece of work the posts of each pair will be separated a greater or less distance so as to engage the work at more or less widely separated points, thereby steadying the device .and increasing the accuracy thereof.

It is preferable that one of the pivots 4 shall consist of a bolt 14 upon which is threaded a thumb nut 15 so that by tightening the nut, the members comprising the frame of the device may be locked against relatively movement after the desired adjustment has been obtained.

Having thus described the invention, what is claimed as new is:

1. In a device of the class described,

crossed pivoted center bars, oppositely arranged sets of side bars, the bars of each set being pivotally connected at their inner ends and between their ends being connected pivotall with the ends of the center bars, a mar ing element located at the pivot for the center bars, and a work-engaging element carried and supported solely by the outer ends of each of the side bars.

2. In a device of the class described, crossed pivoted center bars, oppositely arranged sets of side bars, the bars of each set being pivotally connected at theirinner ends and between their ends being connected pivotally with the ends of the center bars, a markin element located at the pivot for the center ars, and work-engaging elements carried by the outer ends of the side bars, the center bars being of greater length than the side bars whereby when the frame is adjusted for application to work of relatively large size, the work-engaging members at each side of the frame will be relatively separated.

In testimon whereof I aifix my signature.

FRAN IS H. BRENNAN. [1..s.] 

